How to Measure Your Windows for Blinds (Complete Guide)

Made-to-measure blinds are cut to your exact window, which means the single biggest factor in how well a blind fits and functions is the measurement it's ordered against. Get it right and the blind sits flush, glides smoothly and blocks light at the edges the way it should. Get it wrong by even a centimetre and you'll notice it every day. Here's how to do it properly.

Inside mount or outside mount?

Decide this first, because it changes what you measure.

• Inside mount — the blind fits within the window recess, giving a clean, built-in look. You need at least 6–7cm of recess depth for the bracket to sit properly.
• Outside mount — the blind is fixed to the wall or frame above the window, covering the recess entirely. This is the better choice for shallow recesses, or when you want maximum light blockage at the edges.

Measuring for an inside mount

1. Measure the width of the recess at the top, middle and bottom. Use the smallest of the three measurements — recesses are rarely perfectly square.
2. Measure the height at the left, middle and right. Again, use the smallest figure.
3. Check the recess depth is enough to clear any window handles, locks or sills the brackets would otherwise collide with.

Measuring for an outside mount

1. Decide how far beyond the window frame you want the blind to extend on each side — 7–10cm total overlap (roughly 3–5cm per side) gives good light blockage without looking oversized.
2. Measure the total width you want the blind to cover, frame plus overlap.
3. Measure the height from where the top fixing will sit down to where you want the blind to end — typically 5–10cm below the sill, or to the floor for a fuller look.

Three things people get wrong

• Measuring only once. Windows and recesses are rarely perfectly square — always take three measurements and use the smallest.
• Using a fabric tape measure. It stretches. A metal tape gives a far more reliable reading.
• Forgetting obstructions. Handles, locks, alarm sensors and sills can all get in the way of an inside-mount bracket — check before you order.

If any of this feels fiddly, you don't have to do it yourself. We offer a completely free site measurement visit across Delhi NCR — one of our surveyors comes to you, takes the exact measurements, and you order with total confidence. You can also try our AR self-measure tool if you'd rather do it digitally from your phone.